Children should steer clear of their parents’ sex lives. The Guardian

A few months ago, my 68-year-old father gave me his old laptop. But he hadn’t logged out of an account, and I discovered he was declaring his love for someone not his wife/my mother.

I challenged him, after which he informed my mum and brother that I was causing trouble. They believed me, although I have not had the best of relationships with either of them.

After four weeks of insulting me, blaming my mum and everyone else, denial and obfuscation, he admitted he’d had unprotected sex with the woman, a supposed family friend he was helping, and that she is in prostitution. He also had an affair 35 years ago when my brother was a baby.

My mum has decided not to take any action, but to carry on as they were because she can’t bear the stress of the upheaval and is worried about money and her home, despite our assurances that she would be OK. She is not a confident person, was depressed after the last known episode, and is quite isolated.

I am livid at my father’s behaviour. I doubt very much he hasn’t been up to something in the intervening years. He had presented himself to me as a model, kind, caring man and I fear I have enabled his egotism over the years by being daddy’s girl. I never want to have any contact with him again. I am perturbed by my mum’s acceptance of the situation and by how much worse things could get if he carries on behaving this way. How can I support my mum but also not allow him to get away with what he has done?

I understand that you are hurt, that perhaps your father isn’t the man you thought he was. I understand you are angry at your mother for the things you see she has failed to do. But children should never get involved in the business of parents’ sex lives, and once the hurt and confusion fades I think you need to think about why your reaction is so extreme.

Sure, be annoyed with your mum or dad for a myriad of other reasons but I think you are a bit confused about what is your business, and what isn’t. It’s their sex life, not yours. Talking of which, there was no mention in your letter of your own personal life.

I consulted couples psychotherapist Joanna Rosenthall (bpc.org.uk), who wondered whether things might have got out of balance in your family. She thought you sounded almost as if you felt your dad had been unfaithful to you. She said these imbalances might be caused if a child hadn’t been helped to separate out and learn to be outside their parents’ relationship.

For example, such a child may have been used as a confidante too often or too early in life or both. This demarcation – between your own life and your parents’ – is crucial to your own identity and not being recruited into a “couple” with one of them. “The couple relationship between two adults,” Rosenthall explains, “is very different to that between a parent and child, and there should be no confusion between the two.”

Also if we over-identify with people, in this case your parents, when they let us down or we think we don’t know “who they are any more”, it rather makes us feel we don’t know who we are any more either. And I feel a little bit of that is happening here.

I think it’s important to acknowledge that anyone would be upset by their father having an affair and taking risks, but that shouldn’t really lead to one becoming over-involved in what happens next. It really is between your mum and dad.

You seem really angry with your mum for her choices but maybe, for her, they are the only ones she has. Just because your mum won’t do what you think she should do, doesn’t mean you can’t still support her if you choose.

Rosenthall wondered if you were trying to parent your own parents: “Children sometimes have been invited into that position and it makes it very hard for them to develop a solid, separate identity of their own. There’s something terribly important about people feeling independent enough to make their own decisions and leaving their parents to make theirs.”

When we get out-of-proportion angry with a situation, we need to look at why. You sound as if you feel “hoodwinked” by your dad and I wonder if that played out in your life – your experiences of other men perhaps? – and maybe that was making you extra angry.

So, what can you do? “Support,” says Rosenthall, “is about doing just that – supporting, not judging. Applying pressure never feels supportive.”

Adult relationships between a couple are sophisticated, multilayered. Often confusing to others looking in. I hope you can find a way of supporting your parents while at the same time realising they are not perfect – I know that’s an illusion-shattering moment. This may involve pressing pause on your relationship with them for a while, as you step back and attend to your own needs.

This article first appeared in the Guardian Family section on 26 June 2015.